Not to sound like a nerd, but if you are referring to the part when the Orc is about to gut Frodo and Sam kills him, it seems like there won't be any Orcs for quite a few levels, since Sam came in from the bottom of the tall tower, so even if there were Orcs, they'd be just entering the tower, and since the not-glowing sword is only shown a couple seconds before Sam drops it, it doesn't seem like there is a real slip-up here